Pacemakers and ICDs
A permanent pacemaker is a small electrical device, surgically implanted in the upper chest, which monitors every heartbeat. The procedure is performed in the Cardiac Catheterization Lab, usually under local anesthesia.
There are many variations of arrhythmias, so a cardiologist must select the proper pacemaker and have it electronically programmed for your specific needs.
The pacemaker monitors heart rhythms as programmed by the cardiologist. When necessary, the pacemaker emits tiny electrical signals to stimulate the heart when the heartbeat becomes too slow, fails to beat within a certain period of time, or if the atria or ventricles beat with no relationship to each other.
Information from the pacemaker can be sent from the telephone to the doctor's office. If adjustments need to be made, they will be taken care of in your doctor's office. Follow-up visits with your physician will be scheduled.
A recently approved pacemaker uses wireless cellular technology to remotely monitor the pacemaker and patient. This device can be programmed to automatically transmit data about the patient's current condition and the pacemaker system to the physician's office anytime, and from anywhere cellular services are available.
The wireless system requires no patient action. This means that as long as the patient carries the cellular communication device, they can maintain a normal daily routine while their pacemaker maintains regular contact with the physician's office.
The pacemaker communicates with a cellular transmission device similar to a cell phone. Communication from the pacemaker to the doctor's office occurs in several steps but typically takes only minutes to complete. First, the data is sent from the pacemaker to the communication device, which then transmits the data to a service center.
The data is compiled and then faxed to the physician's office in the form of a "Cardio Report." To safeguard the data and ensure accurate transmission, the home monitoring system uses multiple security techniques.
ICD (Implantable Arrhythmia Control Device)
An AIACD (Automatic Implantable Arrhythmia Control Device) is an implanted device used to detect and terminate dangerous ventricular arrhythmias. The generator is two thirds the size of a deck of cards, and is implanted under the collarbone. One or two wires connect the heart and the device through a large vein.
These wires transmit heart rhythm information to the generator, which processes the input and decides whether a pacing therapy or shock is necessary to restore normal beats. It's like having a "paramedic in the chest." This procedure is performed in the Electrophysiology Lab.
Since implantation is a surgical procedure, the patient stays in the hospital for a few days to recover and to determine if the AIACD needs to be electronically adjusted. During this time, the patient and family members receive instructions regarding special considerations to be taken after discharge from the hospital.
Sometimes a repeat EP study is required to reprogram the device before going home. After the patient leaves the hospital, the cardiologist can analyze and make adjustments in the office if needed. Additional patient and family education is provided during office visits.
Pacemaker Improvements - A Historical Perspective
When pacemakers became a common procedure 35 years ago, it was noted that implantation of the pacemaker was followed in many patients by death. However, it turned out that the reason for premature death from pacemaker implantation had to do with the underlying heart disease and not the pacemaker. It wasn't possible then, as it is now, for cardiology or surgical procedures to interrupt a large myocardial infarction (heart attack).
The result was significant damage to the heart's electrical conduction system as well as to the heart muscle. Not infrequently pacemakers were required just because so much heart muscle was damaged. Therefore, the patients tended to succumb to their underlying heart disease. Although this was associated with pacemaker implantation, in reality the pacemaker did help the patient and had nothing to do with the patient's demise.
Improved Technology and Understanding
In the modern era things are different. Pacemaker implantation is generally uncomplicated, most if not all of the technical issues associated with pacemakers have been solved. Programming of the device is now software-based rather than hardware-based. It's now possible to change "what kind of pacemaker it is" based on the physiologic needs of the patient.
In addition, early recognition and treatment of the underlying heart disease has allowed patients to live much longer, with the pacemaker being only part of a larger, more complex and comprehensive treatment of heart disease. Patients at high risk for sudden death are no longer treated with pacemakers, but are now treated with devices that are combination pacemakers, implantable arrhythmia management devices and defibrillators.
New Therapies, Reactive Technology
More recently, we have learned that continuous pacing of the right ventricle is harmful to the heart in some patients because pacing the right ventricle is associated with desynchronization of the left ventricle, promoting congestive heart failure. This is why biventricular pacing has emerged as a new therapy for patients with heart dysfunction or heart failure who require a permanent pacemaker.
In addition, new technology has allowed us to pace the top chambers or atria without pacing the ventricle except at times when the pacemaker decides that right ventricular or left ventricular pacing is needed. It is only because of the technology developed by the implantable arrhythmia management device that we are able to offer patients these new functions.